Excellent Game!
Just challenging enough (although there are a few glitches and "cheap deaths" here and there.
There were a few instances where the hit detection was a little off (sometimes I would shoot someone within range, and they would not get hit). But overall, it was a solid game, and the satisfaction of blowing enemies arms off with blood and gore to match added a certain morbid hilarity.
And to the people complaining about bowling balls... just step through each level slowly and you won't have to deal with more than one enemy at a time, and the bowling balls will only appear on their own and you can jump over them safely. The trick is to save all your lives for the final boss, and when you face him, just unload on him while jumping over the skull thingys.